You should be careful with what you say around a pregnant lady: according to a new research, there has been evidence that an unborn fetus can hear and recall specific words from its surroundings, during and in the days following birth.

This is a study out of the University of Helsinki, which compliments previous investigations. In this study, the team used EEG scans on 33 newborn babies to reach that conclusion. As expected the research began when the babies were still in the womb: moms-to-be in their third trimester were divided into two groups, with only one group listening to repeating sequences of a nonsensical word (“tatata”). Occasionally, the word would be delivered with a subtle tweak in pronunciation or tone. In all, some study participants listened to that same word a whopping — and probably insufferable — 25,000 times.

Once the babies learn a sound, if it’s repeated to them often enough, they will form a memory of it

After five days following birth, the team played those same recordings to each newborn. Babies who’d been exposed to the sounds in the uterus showed a specific pattern of enhanced brain activity when they heard the word, as well as a reaction known as “a mismatch response” when they heard the altered version of “tatata.” It is based on these reactions, researchers concluded that the babies would literally the word and its conventional delivery. According to Eino Partanen, a cognitive neuroscientist and the study’s lead author “Once we learn a sound, if it’s repeated to us often enough, we form a memory of it, which is activated when we hear the sound again” as he explained to Science. “This leads us to strongly believe that the fetus can learn much more detailed information than we previously thought.”

Other research has suggested that babies familiarize themselves with the patterns of their native language before they’re born. But by evaluating neural patterns rather than simple behavior, and by indicating that babies may recall discrete words heard in the womb, this new study is a robust addition to that existing body of evidence.